SECONDARY EFFECTS OF CANOPY DIEBACK: THE EPIGEAL CARABID FAUNA IN QUÉBEC APPALACHIAN MAPLE FORESTS

Abstract

AbstractThe impact of canopy dieback on the activity and diversity of epigeal Carabidae was studied during the summers of 1987 and 1988 in 18 maple stands in southeastern Québec, using pitfall traps. A canopy thinning index (CTI) based on severity and incidence of dieback, and on tree basal area was calculated for each of the 72 stations sampled. An analysis of variance shows that canopy dieback had a significant effect on carabid beetle activity in 1988. The CTI was negatively correlated with the carabid species richness and diversity in 1988. The number of individuals caught per station was negatively correlated with the CTI for all species combined, except for the dominant Pterostichus coracinus Newm. in 1988. These results indicate a negative response of carabid beetles to canopy dieback in 1988; the climate may have tempered the effects of dieback in 1987.